Catalase protection against hydrogen peroxide-induced injury in rat oral mucosa

Hydrogen peroxide in contact with the oral mucosa induces vesicle formation and ulceration. This study assesses the protective effect of catalase against the hydrogen peroxide insult in the rat tongue mucosa. In addition, we report a detailed histologic characterization of the mucosal injury. Four repetitive applications of 30% hydrogen peroxide at 15 minute intervals produced a vast edema of the submucosal tissue including the tongue muscles that was seen immediately after the last application. Histomorphometric measurements indicated a substantial regression of the edema 1 day later with the appearance of a very large ulceration lined by a pyogenic membrane. Animals examined 7 days after the hydrogen peroxide administration revealed almost complete healing in terms of absence of edema and renewal of intact epithelial lining. Catalase applied to the tongue before the hydrogen peroxide fully prevented the pathologic tissue reaction. Thus testing of the clinical feasibility of catalase in protecting the oral mucosa against hydrogen peroxide-induced injury is strongly indicated.